So surface agitation is not bad in a planted tank?

When I did a planted tank a looong time ago I was taught that any surface agitation was bad for a planted tank due to the fact that it helped in reducing Co2 which the plants need desperately in the water column.

When I did a planted tank a looong time ago I was taught that any surface agitation was bad for a planted tank due to the fact that it helped in reducing Co2 which the plants need desperately in the water column.

Thanks for any insights into this.

Hello plant...

You're correct. Oxygen is a plant waste product, so an environment high in oxygen wouldn't be good for your plants. However, I use lengths of plastic tubing attached to an air pump and I run the end of the tubing in the bottom of my tanks. The water movement from the large bubbles circulate the water, so nutrients pass through the plant roots. I believe the water movement helps plant growth.

I flirted with tank crash for a month or two when I had inadequate surface agitation as well as uneven C02 distribution. Now, I have a spray bar that runs along one end of the tank, aimed the length of the tank and upward as well as a smaller powerhead aimed upward and towards the opposite corner of the tank to help push the flow along. It essentially pushes the water in a large loop down the length of the tank and I was surprised to see how much better the C02 flowed throughout the entire aquarium. It also allows you to crank up your C02 as well. More oxygen in the water means that more C02 can be pumped into the tank.

There is a balance between too much and not enough. As noted above, the tank does need water movement. At the surface, water movement enhances gas exchange, which can ADD CO2 in the right circumstances and reduce surface scum.
Deeper in the tank water movement keeps the fertilizers and so on in motion, bringing them closer to the plants, and keeps the debris in motion, bringing it closer to the filter intake for removal.

If you are adding CO2, pressurized or DIY, then too much water movement can release some of the CO2 to the air. But even then the tank needs some water movement. Adding CO2 is not adding oxygen for the livestock. There still needs to be an exchange.

How much is 'not enough' or 'too much' will depend on a lot of things, it is best to watch the fish and plants while you try different levels, and different arrangements of the equipment.
Fish from a fast flowing stream will thrive in fast moving water, fish from a lake, or slower moving stream will not like that much water movement. Fish can move to different areas of the tank. If they are always hanging out where the water movement is the strongest, I would add more water movement. If they are always hiding in the slowest moving corners then I would reduce the water movement. Fish that spend time in both areas are telling you the tank is set up just right for them.
I am looking at my Congo Tetras, and one is hanging out really close to the power head, I think he is going to get out his surfboard! The others are mid tank, in some water movement, just not right in front of the PH. The Loaches occasionally 'surf' the PH, but mostly play around on the bottom.
Too much water movement stresses the plants, doing a small amount of tissue damage. Gently waving plants seems to be a good amount of water movement, but, like fish, it depends on the plant. I have some Pennywort that is going crazy right on top of a power head, water is rippling as much as 1/2" up and down. Bolbitis seems to thrive right in the path of fast moving water.

How much is 'not enough' or 'too much' will depend on a lot of things, it is best to watch the fish and plants while you try different levels, and different arrangements of the equipment.
Fish from a fast flowing stream will thrive in fast moving water, fish from a lake, or slower moving stream will not like that much water movement. Fish can move to different areas of the tank. If they are always hanging out where the water movement is the strongest, I would add more water movement. If they are always hiding in the slowest moving corners then I would reduce the water movement. Fish that spend time in both areas are telling you the tank is set up just right for them.

I've had to add a nano power head to my 29g to address a dead spot but I've noticed the tetras move to a quiet corner behind the dead spot, where incidentally I'm still seeing pockets of BBA. I've since put the PH on a timer synchronized with the CO2. Are there any problems with this approach?

There is a balance between too much and not enough. As noted above, the tank does need water movement. At the surface, water movement enhances gas exchange, which can ADD CO2 in the right circumstances and reduce surface scum.
Deeper in the tank water movement keeps the fertilizers and so on in motion, bringing them closer to the plants, and keeps the debris in motion, bringing it closer to the filter intake for removal.

If you are adding CO2, pressurized or DIY, then too much water movement can release some of the CO2 to the air. But even then the tank needs some water movement. Adding CO2 is not adding oxygen for the livestock. There still needs to be an exchange.

How much is 'not enough' or 'too much' will depend on a lot of things, it is best to watch the fish and plants while you try different levels, and different arrangements of the equipment.
Fish from a fast flowing stream will thrive in fast moving water, fish from a lake, or slower moving stream will not like that much water movement. Fish can move to different areas of the tank. If they are always hanging out where the water movement is the strongest, I would add more water movement. If they are always hiding in the slowest moving corners then I would reduce the water movement. Fish that spend time in both areas are telling you the tank is set up just right for them.
I am looking at my Congo Tetras, and one is hanging out really close to the power head, I think he is going to get out his surfboard! The others are mid tank, in some water movement, just not right in front of the PH. The Loaches occasionally 'surf' the PH, but mostly play around on the bottom.
Too much water movement stresses the plants, doing a small amount of tissue damage. Gently waving plants seems to be a good amount of water movement, but, like fish, it depends on the plant. I have some Pennywort that is going crazy right on top of a power head, water is rippling as much as 1/2" up and down. Bolbitis seems to thrive right in the path of fast moving water.

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